Revision Note: V1.0 (April 14, 2015): Advisory published.
Summary: Microsoft is announcing the availability of a defense-in-depth update that improves the authentication used by the Public Key Cryptography User-to-User (PKU2U) security support provider (SSP) in Windows 8.1, Windows Server 2012 R2, and Windows RT 8.1. The improvement is part of ongoing efforts to bolster the effectiveness of security controls in Windows.